Everton are to offer Ross Barkley a new long-term contract that reflects his emergence as one of the finest young talents in England.

The 20-year-old has two and a half years remaining on the lucrative deal he signed in December 2011 but after he has begun to fulfil long-held expectations at Goodison Park this season, Everton plan to open talks on extending and improving Barkley's terms. The club want to reward the midfielder's impact as a Premier League regular and also deter inevitable suitors before a summer that is likely to feature a World Cup in Brazil for their homegrown talent.

"Ross has got a long-term contract with us so it is not a situation where he is coming to the end of his contract," said Roberto Martínez, the Everton manager. "As a club, we will always want to reward young players if they do well in the first team and their roles change. Remember that Ross was a youngster trying to break into the first-team squad. Now, for me, he is going to have an important role in the squad, so that is going to be reflected. But there is not a timescale [on the contract being signed]."

Everton have always been proactive on Barkley's contract situation, handing the England international a maximum two-and-a-half-year contract at 17, when he was recovering from a triple leg fracture, and replacing that with a four-and-half-year deal days after his 18th birthday. Negotiations on his latest contract, however, are yet to commence.

Martínez said: "It is something that is in my thoughts. As soon as we conclude that, we will let the fans know. It is the same for every young player, not just for Ross. Every youngster that comes in and allows himself to step up into a new role, that is going to be recognised in a contract. If his contract is up at the end of the season or he has another five years, it doesn't matter."

Manchester United and Chelsea were among those interested in Barkley before he turned 18 and made a handful of appearances for Everton under David Moyes, but it is only this season under Martínez that the Liverpool-born midfielder has established himself as a first-team regular. And Barkley, advised to remain at Everton by the Liverpool captain Steven Gerrard, admits Martínez's appointment has been crucial to his emergence.

Barkley, who was loaned to Sheffield Wednesday and Leeds United during Moyes's tenure, said: "I knew when I heard he was coming in that I'd get my chance this season. I'd seen the way he was with Callum McManaman and James McCarthy at Wigan, that he gives young players their chance. I knew I was the type of player to suit him because he's a really tactical manager who likes to build up the play. So I felt confident this could be the season I'd break through."

Everton are also looking to extend the contracts of Leighton Baines and Sylvain Distin, who have 18 and six months remaining on their current deals respectively.

"Sylvain has been a terrific performer this season and we couldn't be happier with his role at the club," said Martínez, who would not be drawn on the specifics of Baines's contract negotiations. The England left-back is likely to be subject of renewed interest from Manchester United in January. "All these issues are vital for us and we are going to look after them straight after this Christmas period. At this moment all that matters is to get everyone focused in being ready to help the team and Sylvain clearly has been an example of doing that."